The disclosed embodiments relate to a medical device. Specifically, the disclosed embodiments relate to a catheter in which a tip is joined to a distal end of a catheter shaft.
When a stenosis site or blockage is formed in a blood vessel, a bile duct, a pancreatic duct, or the like, the flow of blood, gall (bile), pancreatic juice, or the like, respectively, is disrupted. As a method of treating such a stenosis site or blockage, a treatment using a catheter is widely performed.
Generally in a catheter, a flexible tip is joined to a distal end of a catheter shaft including a reinforcing layer (see U.S. Pat. No. 5,769,830, for example). In this manner, the rigid catheter shaft maintains the operability of the catheter, while the flexible tip reduces potential damage to duct walls of a blood vessel, a bile duct, a pancreatic duct, or the like when the catheter is inserted therein.
However, in such a catheter, the tip is only joined to the distal end of the catheter shaft. The joining strength between the catheter shaft and the tip is small, and the tip can detach from the catheter shaft when a technician operates the catheter while the tip is caught by a stenosis site or blockage.
Moreover, when the catheter is inserted into a highly bent blood vessel, bile duct, pancreatic duct, or the like, stress is concentrated at a boundary portion between the tip and the catheter shaft, which can cause the tip to break at the boundary portion.